Introduction
[0001] The present invention relates to free-standing chimney assemblies of the type comprising
a number of prefabricated components assembled together to form a fireplace communicating
by a combustion gases vent hole with a vertically arranged gas flue.
[0002] Such prefabricated assemblies are used extensively in buildings and particularly
in buildings such as timber-frame buildings and the like. It is known, for example,
in timber-frame buildings to build up free-standing chimney assemblies by conventional
blocks and mortar. Such free-standing chimney assemblies are banned for use with party
walls within timber framed housing because of poor quality control in erecting the
chimney. Even when they do comply with building regulations they have the problem
that very often the chimneys are not vertical in that it is almost impossible to build
them sufficiently accurately by conventional means and to provide a chimney assembly
that is structurally sound. This is one of the main reasons why free-standing chimney
assemblies are provided where the components comprise a number of relatively large
prefabricated components assembled together.
[0003] Unfortunately, prefabricated chimney assemblies have not heretofore been particularly
successful. They have either been very difficult to assemble or alternatively, have
not been sufficiently rigid in use. Further, what is required is a free-standing chimney
assembly that can be made in many configurations. Thus, for example, it should be
possible to have a free-standing chimney assembly that forms part of the outer wall
of the house in which case the free-standing chimney assembly may encompass only one
fireplace. In other situations, it should form an interior wall of the house which
is often the most preferable construction, which chimney, being incorporated in the
interior wall of the house, would almost certainly be required to provide two fireplaces
for back to back rooms in the house.
[0004] The present invention is directed towards providing such a construction of free-standing
chimney assembly, which will be relatively easy to assemble, structurally rigid and
which will integrate conveniently into the surrounding structures such as the walls
of the house or the party wall between two houses.
Statements of Invention
[0005] The invention provides such a free-standing chimney assembly of the type comprising
a number of prefabricated components assembled together to form a fireplace communicating
by a combustion gases vent hole with a vertically arranged gas flue, characterised
in that:
the fireplace comprises a one-piece fireplace enclosure having base, top, side and
back walls;
the gas flue comprises an inner flue member formed from a plurality of interengaging
flue pipes communicating with the combustion gases vent hole and in which there is
a main support structure comprising a plurality of main flue blocks, having a block
bore larger than the outside diameter of the flue pipe, each mounted one on top of
the other on the fireplace enclosure to receive the flue pipes and define an enclosure
therebetween for reception of heat insulation material to encompass the flue pipes;
and
connecting means for securing the main flue blocks in position.
[0006] The advantage of having this assembly is that it is relatively easy to assemble and
it will form a vertical and rigid structure. Ideally, the flue pipes are surrounded
by an insulation material.
[0007] In one embodiment of the invention the one-piece fireplace enclosure forms two separate
fireplaces with a common back wall and parallel flues, the flue pipes adjacent the
combustion gases vent provide a transition bend in the flue so that the parallel flues
are moved through a right angle between the fireplace and the top of the chimney,
in which intermediate flue blocks are mounted between the main flue blocks having
a pair of side-by-side block bores and in which the intermediate main flue block has
a block bore to accommodate the two flues. By providing the intermediate main flue
blocks it is relatively easy to arrange the flues initially, for example, on either
side of a party wall and then to crank them to lie parallel to the party walls as
they are led up the building to exit the building.
[0008] Ideally there is provided a longitudinally arranged open air vent slot is formed
in the main flue block bore. The advantage of this is that it ensures that there is
an adequate flow of air around the flue to ensure for example, if there is any leak
of combustion gases through the flues that they will be taken to atmosphere. It also
aids in cooling the assembly and provides good heat transfer when required.
[0009] Preferably there are four vent slots equi-spaced circumferentially around the block
bore. This is a particularly useful construction.
[0010] Ideally the connecting means comprises:
a plurality of sets of interconnected vertically arranged tie-bars each set engaging
in-line through-holes in the main flue blocks, each bar having threads adjacent each
end for reception of an internally threaded sleeve connector, the through-holes in
the blocks having enlarged distal and proximal bores for reception of the sleeve connectors;
and
a threaded socket in the top of the fireplace enclosure for anchoring of the set of
bars.
[0011] By using separate short lengths of bar it is possible to tighten the various parts
of the chimney together, without imposing undue strain on adjacent parts. While at
the same time by connecting them all in effectively the one tie-bar the overall assembly
is adequately secured.
[0012] Ideally each of the flue blocks and the sides of the fireplace include a laterally
projecting wall anchorage rib having an end face and two side faces, the side faces
forming supports for spaced apart wall panels. This allows the party walls to be easily
mounted adjacent the chimney assembly thus providing a very rigid unit.
[0013] Ideally the components are manufactured from a light-weight concrete. Light-weight
concrete is particularly suitable because it allows for ease of assembly and the relatively
light weight minimises difficulties in manipulating the components and placing them
one on top of the other.
Detailed Description of the Invention
[0014] The invention will be more clearly understood from the following description of an
embodiment thereof, given by way of example only described with reference to the accompanying
drawings in which:
Fig. 1 is a perspective view of a construction of chimney assembly according to the
invention;
Fig. 2 is a front view of the chimney assembly on the side of a house;
Fig. 3 is a perspective view of portion of a chimney assembly according to the present
invention in a party wall of a house;
Fig. 4 is an exploded view of portion of the chimney assembly illustrated in
Fig. 3;
Fig. 5 is a front view of a fireplace forming part of the chimney assembly;
Fig. 6 is a sectional view along the lines VI-VI of fig. 5;
Fig. 7 is a sectional view along the lines VII-VII of Fig. 6;
Fig. 8 is a sectional view along the lines VIII-VIII of Fig. 7;
Fig. 9 is a sectional view along the lines IX-IX of Fig. 5;
Fig. 10 is a plan view on an enlarged scale of an intermediate main flue block according
to the invention;
Fig. 11 is a side view of the intermediate main flue block;
Fig. 12 is a front sectional view of the intermediate main flue block along the lines
XII-XII of Fig. 10;
Fig. 13 is a plan view in an enlarged scale of an upper main flue block;
Fig. 14 is a side view of the upper main flue block;
Fig. 15 is a side sectional view of the upper main flue block along the lines XV-XV
of Fig. 13.; and
Fig. 16 is a side view of tie bars and sockets according to the invention.
[0015] Referring initially to Figs. 1 to 4 and particularly Fig. 1 of the drawings, there
is illustrated a free-standing chimney assembly, indicated generally by the reference
numeral 1 comprising a one-piece fireplace 2, an inner flue member formed by a pair
of sets of inner flue pipes 3 over the fireplace 2 and surrounded by a main support
structure formed by upper main flue blocks 4 and intermediate main flue blocks 5.
External cladding 6 and a chimney plate 7 are illustrated, these do not form part
of the invention. Heat insulation material 8 is shown in Fig. 3 surrounding the inner
flue pipes 3.
[0016] Referring now to Figs. 5 to 9 inclusive, the fireplace 2 comprises a one piece enclosure
forming two separate fireplaces with a common back wall 10, base 11, top 12 and side
walls 13. Mounted in each top wall 12 is a combustion gases vent hole 14. A laterally
projecting rectangular wall anchorage rib 15 having an end face 16 and a pair of side
faces 17 projects from each side wall 13. Holes 18 are provided in the top 12 for
reception and anchorage of threaded sockets, not shown.
[0017] Referring now to Figs. 10 to 12, an intermediate main flue block 5 is illustrated
in which parts similar to those described with reference to the previous drawings
are identified by the same reference numerals. Thus, parts such as the wall anchorage
rib 15 is not described again. Each intermediate main flue block 5 is a substantially
octagonal block having a hollow block bore 20, top 21 and bottom face 23 and side
faces 24, through-holes 25 having enlarged bores at their proximal and distal ends
form socket retaining recesses 26 at the top face 21 and the bottom face 23.
[0018] Referring now Figs. 13 to 15 inclusive which illustrates the main flue block 4 parts
similar to those described with reference to the previous drawings are identified
by the same reference numerals. The main flue block 4 has a pair of block bores 30
communicating between top and bottom faces 31 and 32, respectively, the internal diameter
of the block bore 30 is greater than the outside diameter of each inner flue member
3. Four longitudinally arranged open-air vent slots 33 are provided equi-spaced around
the block bore 30. Through-holes 25 and respective recess 26 are again provided as
are the ribs 15.
[0019] Referring now to Fig. 16, there is illustrated a connecting means indicated generally
by the reference numeral 40, for securing the chimney assembly in position, said connecting
means 40 comprising a plurality of sets of interconnected tie-bars 41 having adjacent
each end threads 42 for reception of an internally threaded sleeve connector 43.
[0020] In operation, to construct the chimney assembly and referring initially to Fig. 4
the fireplace assembly 2 is placed in position and a pair of inner flue pipes 3 are
mounted in the combustion gases vent holes 14 and some of the inner flue pipes 3 are
so-configured as to provide a 45° bend in each flue so that the parallel flues are
moved through 90° between the fireplace and the top of the chimney. Intermediate flue
blocks 5 are then mounted on the fireplace assembly 2 and tie-bars 40 are mounted
in the fireplace assembly 2 and some of the intermediate blocks 5 are formed one on
top of each other and are grouted into position. Then the tie-bars 40 are tightened
together by means of the sleeve connectors 42. A number of main flue blocks 4 are
then placed in position. Further inner flue pipes 3 are placed in position and the
outside of the flue pipes 3 is covered with the heat insulation material 8. Again
when sufficient main flue blocks 4 have been placed in position, further tie-bars
40 and sleeve connectors 42, together with grouting are used to secure the main flue
blocks 4 in position. The building then continues up the whole chimney until the entire
chimney is assembled. Fig. 3 shows the building of a party wall 50 formed from two
panels 51 mounted against the side faces 17 of the rib 15 sandwiching insulation panels
52 therebetween.
[0021] While in the embodiment described above the chimney has been illustrated between
two walls of a house, the chimney could equally well be constructed as a single fireplace,
in which case the fireplace assembly would contain only one fireplace. The remainder
of the construction would be exactly the same as heretofore, except that there would
be no need for intermediate flue blocks and the main flue block would simply contain
one hole for reception of a flue pipe.
[0022] Ideally the chimney assembly according to the invention is manufactured from a light
weight concrete.
[0023] In the specification the terms "comprise, comprises, comprised and comprising" or
any variation thereof and the terms "include, includes, included and including" or
any variation thereof are considered to be totally interchangeable and they should
all be afforded the widest possible interpretation and vice versa.
[0024] The invention is not limited to the embodiment hereinbefore described, but may be
varied in both construction and detail within the scope of the claims.
1. A free-standing chimney assembly (1) of the type comprising a number of prefabricated
components assembled together to form a fireplace communicating by a combustion gases
vent hole with a vertically arranged gas flue, characterised in that:
the fireplace (2) comprises a one-piece fireplace enclosure having base (11), top
(12), side (13) and back (10) walls;
the gas flue comprises an inner flue member formed from a plurality of interengaging
flue pipes (3) communicating with the combustion gases vent hole (14) and in which
there is a main support structure comprising a plurality of main flue blocks (4, 5),
having a block bore larger than the outside diameter of the flue pipe, each mounted
one on top of the other on the fireplace enclosure to receive the flue pipes and define
an enclosure therebetween for reception of heat insulation material to encompass the
flue pipes; and
connecting means (40) for securing the main flue blocks (4, 5) in position.
2. A chimney assembly (1) as claimed in claim 1, in which the flue pipes (3) are surrounded
by an insulation material (8).
3. A chimney assembly (1) as claimed in claim 1 or 2, in which the one-piece fireplace
enclosure forms two separate fireplaces (2) with a common back wall (10) and parallel
flues, the flue pipes (3) adjacent the combustion gases vent hole (14) provide a transition
bend in the flue so that the parallel flues are moved through a right angle between
each fireplace (2) and the top of the chimney, in which intermediate main flue blocks
(5) are mounted between the upper main flue blocks (4) having a pair of side-by-side
block bores (30) and in which the intermediate flue block has a block bore (20) to
accommodate the two flues.
4. A chimney assembly (1) as claimed in any preceding claim, in which a longitudinally
arranged open air vent slot (33) is formed in the main flue block bore (30).
5. A chimney assembly (1) as claimed in claim 4, in which there are four vent slots (33)
equi-spaced circumferentially around the block bore (30).
6. A chimney assembly as claimed in any preceding claim in which the connecting means
comprises:
a plurality of sets of interconnected vertically arranged tie-bars (41) each set engaging
in-line through-holes (25) in the main flue blocks (4, 5), each tie-bar (41) having
threads (42) adjacent each end for reception of an internally threaded sleeve connector
(43) , the through-holes (25) in the main flue blocks (4, 5) having enlarged distal
and proximal bores (26) for reception of the sleeve connectors (43); and
a threaded socket in the top of the fireplace enclosure for anchoring of the set of
tie-bars (41).
7. A chimney assembly (1) as claimed in any preceding claim in which each of the main
flue blocks and the sides of the fireplace include a laterally projecting wall anchorage
rib (15) having an end face (16) and two side faces (17), the side faces (17) forming
supports for spaced apart wall panels.
8. A chimney assembly (1) as claimed in any preceding claim manufactured from a light-eight
concrete.